Brettus

iTrader: (2)

This all sounds very good & I think I could be swayed but the thing that weighs heavily on my mind is all the blown motors & failed turbos I keep hearing about .
There aren't enough SC conversions out there yet to say it will be any different however.

As far as where I live - I really only have the Rotormaster SC available to me.

MadDog

Yeah. Its hard to hear about blown motors due to SC bungles when no one has a SC.

swoope

iTrader: (5)

and the rotormaster is selling where in usa?

beers

Brettus

iTrader: (2)

Copied from DNA website ......


Stage 1 Kit Contents: Produces 60% more power at 6psi

ProCharger C-2
All necessary brackets and bolts
All necessary hoses and pipes
6psi pulley
6-rib belt
DNA Motorsport intercooler system
PowerMod Engine Management System
No bodywork cutting what-so-ever
Detailed installation instructions
12 months warranty
Price for Australian Customers (Aus $): $10900 inc GST
Price for USA Customers (US$): $6999
Customers from other countries please contact us for your pricing


Stage 2 kit Contents: Produces 75-95% more power with 8-12psi boost

Stage 1 kit as above
8-12psi pulley
Injector upgrade
Extractors / Headers
Price for Australian Customers (Aus $): $11999 inc GST
Price for USA Customers (US$): $7799
Customers from other countries please contact us for your pricing

swoope

iTrader: (5)

wow,

that is an update..

beers

Brettus

iTrader: (2)

Found this interesting also :

High revving ProCharger C-2 is the perfect match for the high revving Renesis motor. C-2 can spin at an amazing 80,000RPM, pushing 1100CFM of air into the motor, similar to using a T-4 size turbo, according to Joe. Unlike the turbo, C-2 does it easily with only a fraction of the boost. The Renesis motor in the RX-8 runs a high 10:1 static compression, therefore, keeping boost low was one of Joe's primary objectives for a reliable daily driven RX-8.

MazdaManiac

iTrader: (3)

If you only want to drive it at high RPMs

Oh yeah. Amazing. Wow. Turbos can spin in excess of 100,000 RPM. I'm not sure who that was meant to impress - the people who know better, or the people who don't.

That would be 72 lbs of air. Uh, I don't think so. That would require 3000cc of injector capacity.
That isn't like any T4 I've seen on a Renesis. I think I'd like to meet this "Joe".

I'm not sure how they want to explain that. If you push four times the amount of air into the Renesis then I could inject on its own, you would still see 44 PSI of boost even if the compressor were 100% efficient (which it is not, just in case you were actually wondering).

72 pounds of air will make for one crazy power stroke at a 4:1 static compression, let alone a 10:1.
Quick, someone grab the meth before Joe sees it again.

Do people that write copy like this expect only uninformed people to read it?

Hard to blow a motor with an imaginary supercharger.

Brettus

iTrader: (2)

thanks for the response MM however you made it look like I had written all that ....

rotarenvy

has anyone seen a flow map of the procharger C-2?

MazdaManiac

iTrader: (3)

What do you mean? It says "ProCharger Doofus", not "Brettus".
I couldn't have made it any more plain.

Brettus

iTrader: (2)

Bit harsh there MM . Thanks (I think) for changing it .
BTW when they say 1100CFM - that is the capacity of the SC - not what it is flowing in this application.

yes I know that is not how it reads

Charles R. Hill

iTrader: (7)

Not to veer off course but the idea that turbos are banned for reasons of safety is unclear to me as the Top Fuel, Funny Car, and several other Pro classes have blower explosions all the time, not to mention that the import drags are nothing BUT turbos. The most interesting class, to me, is the Pro Mod class because it pits power-adders of all types against one another and no single type is dominant. This season, or maybe it was last and it hasn't yet caught on, they allowed turbos to compete against the already-pouplar nitrous and blown cars. I think the reason it hasn't caught on is that people are afraid to venture into the unknown when your season's budget is in question(as they are every year). A nationally-known and highly-respected racer, Harold Martin, lives down the road from me and last season he switched from carbs to fuel injection. He had a hell of a time getting that sorted out along with the nitrous system he uses. My point is that the sanctioning bodies are becoming more open about technologies but the racers/teams may be slow to embrace them.

mysql101

I could be off base here, but I was under the impression that NHRA doesn't allow turbocharged cars in many classes, and that the same went for (some?) top fuel. Then we all know about the F1 change with banning turbos.

The safer remark was due to limiting max speeds under 330 mph in the quarter mile.

Charles R. Hill

iTrader: (7)

Yeah, that safety is an issue with regard to speed is an accurate one. I am not up to date on the NHRA but the IHRA runs things a little differently. That's why i am a fan of the Pro Mod class in the IHRA. However, we can never really know what the motivation is for certain rules changes unless we are actually in the closed-door sessions of those who run those sanctioninig bodies. Since people are involved many times changes are due to political pressures and not necessarily engineering necessity. But we need to stay on topic, don't we.....?

globi

At least one reason that would speak for a turbocharger on a rotary engine, is the fact that a rotary engine has usually more enthalpy (higher temperature and pressure) left in the exhaust to drive the turbine, which does make the entire set-up more efficient and would also allow for a larger compressor wheel compared to turbos generally used on piston gasoline engines.
(With Diesel-engines it is actually the opposite and they indeed utilize turbos with larger turbine wheels in comparison).

As far as supercharger goes: I wonder whether scroll-compressors are not more popular? Of all positive displacement supercharger it is by far the lightest. This G50 flows up to 460 CFM @ 13,000 rpm and at a weight of only 20 lbs:
http://www.g-laderseite.de/g-lader_z..._g50_fotos.php Also, at least compared to the Roots compressor it is also more efficient.

MazdaManiac

iTrader: (3)

Scroll compressors are not really up to the flow demands of an automobile engine, despite their efficiency.
They also shake like crazy.

globi

Well, scroll compressors need to be balanced (like a piston engine), but then they should run pretty smooth. Also, it's true though this particular scroll compressor G50 is too small for the RX-8, but it was installed on a Renault Spider with a 2l engine which generated almost 300hp with it (at a boost pressure of 1.25 bar).
http://www.renault-sport-spider.de/M...spotStart.html
(scroll down)

I sort of understand why scroll compressors are not more popular in OEM applications because the scrolls actually need to be milled out of a rather big block and they require seals (like the rotary engine), but I don't quite understand why some small series tuners don't produce them. (It should be easier to engineer than lets say an axial flow compressor).

Back to turbos, (this might have been discussed before) but are there people installing larger compressor wheels on turbos utilized on the RX-8?

Spin9k

Here's my favorite design using an Autorotor twin-screw compressor. It's just so compact and efficient looking including the water to air intake intercooler. Sigh....

If only ... it could be a good choice for our small rotary engine bay.

MazdaManiac

iTrader: (3)

How much larger do you want to go?

Here is what I'm running:

globi

Yes, it has a pulsed outlet, but this shouldn't necessarily be a disadvantage on a pulsed engine.

Btw another reason to favor a turbo (besides the higher enthalpy in the exhaust gases) on a Renesis, if you don't mind the jump, is the fact that it doesn't have any overlap (inlet and outlet port), which normally would give a supercharger the opportunity to sweep the exhaust gases completly out of the combustion chamber (and increase VE).

Ok, this looks like plenty. But what I wanted to know, is whether people would utilize turbos with larger compressor or smaller turbine wheels given the fact that there's more enthalpy in the exhaust (than in a piston gasoline engine)?

MazdaManiac

iTrader: (3)

Well, historically, the relationship between compressor and turbine utilized for a rotary has been "upside-down" compared to a piston motor.
For a street application, you match the compressor to the motor and then go 75% larger on the turbine side than would be typical for an equivalent-to-piston result.

globi

Oh, I guess I must be confused then.

MazdaManiac

iTrader: (3)

Well, maybe not. I'm not sure I understood your question.
Generally, higher exhaust heat retention and flow means a bigger turbine for equal response.

Brettus

iTrader: (2)

question for you MM - if you HAD to fit a SC rather than a turbo - which one would you go for ?

MazdaManiac

iTrader: (3)

Hmm. I guess one of the bigger Autorotors - I guess the 3116 or 3133. Or a Sprintex S3-335.
They are compact and have thermal efficiencies close to a turbo and are positive displacement.